The Status of Mottled Duck in Arizona

Articles | By Richard Webster | Accepted January 01, 2007

Searching Cornell’s eBird for “Mexican Duck” (Anas platyrhynchos diazi) does not find it.  If you enter “Mexican Duck” in the species search box of the online “Birds of North America” (BNA), you won’t find it, Although the BNA account of Mallard (Drilling et al. 2002) does contain useful information on Mexican Duck (and a keyword search will find it), it reflects current, official species-level taxonomic treatment of Mexican Duck as a subspecies of Mallard. Moreover, it illustrates how far Mexican Duck has slipped below the radar of both birdwatchers and ornithologists.  The title is deliberately provocative (Mottled Ducks in Arizona?), but it is more relevant than you might think, as this note will explain. Mexican Duck deserves more attention, and there is growing evidence that treatment as a full species is the best course. In this article “Mallard” refers to the green-headed species, “mallard” to the whole complex of 14 or so species, and “Mexican Duck” to, officially, “Mexican” duck, A. p. diazi.